Question: Which station is PBS?
Paraphrase: Which station is PBS?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P1416 wd:Q215616 . ?sbj wdt:P31 wd:Q1616075 } 
Answer: KBDI-TV, KQED, Vermont PBS, WNED-TV, WTVS, KMOS-TV, WTTW, KCET, Alabama Public Television, AlaskaOne, WBRA-TV, East Tennessee PBS, Idaho PBS, Iowa PBS, KACV-TV, KAKM, KAMU-TV, KAWE, KLCS, KOCE-TV, KPBT-TV, Louisiana Public Broadcasting, Milwaukee Public Television, WSEC, Oklahoma Educational Television Authority, Rocky Mountain PBS, W47CO, WCMU-TV, WLIW, WLRN-TV, WPBA, WPBT, WEDQ, WXEL-TV, West Virginia Public Broadcasting, UNC-TV, OC Channel, The Ohio Channel